as·​tro·​labe | \ ˈa-strə-ˌlāb How to pronounce astrolabe (audio) also -ˌlab \

Definition of astrolabe

: a compact instrument used to observe and calculate the position of celestial bodies before the invention of the sextant

Illustration of astrolabe

Illustration of astrolabe

The Astrolabe and the Stars

"Thyn Astrolabie hath a ring to putten on the thombe of thi right hond in taking the height of thinges." Thus begins a description of the astrolabe in A Treatise on the Astrolabe, a medieval user's guide penned by an amateur astronomer by the name of Geoffrey Chaucer. Chaucer is best known for his Middle English poetic masterpiece The Canterbury Tales, but when his nose wasn't buried in his writing, Chaucer was stargazing, and some of his passion for the heavens rubbed off on his son Lewis, who had displayed a special "abilite to lerne sciences touching nombres and proporciouns." Chaucer dedicated his treatise to the 10-year-old boy, setting his instructions not in the usual Latin, but in "naked wordes in Englissh" so that little Lewis could understand. When he got older, Lewis may have learned that the word astrolabe traces to the Greek name for the instrument.

Examples of astrolabe in a Sentence

Recent Examples on the Web There are also lots of smaller instruments—thermometers, sextants, astrolabes—and plenty of globes, as well as an enormous armillary sphere, designed and built by the Italian astronomer Antonio Santucci. Jennifer Ouellette, Ars Technica, 17 May 2020 John has a gift just for Bree, an astrolabe, that allows them to find their position in the universe and tell the time. Maureen Lee Lenker,, 13 Apr. 2020 But that’s because its function is more astrolabe than clock. Alex Schechter, National Geographic, 4 Nov. 2019 Some of the classes included: Social Studies/Math where students created astrolabes and used them outside to measure locations of buildings, trees, etc. and gauge distance and patterns. Sam Boyer, cleveland, 20 Sep. 2019 There also appears to be new imagery shown in the metallic astrolabe or armilla that hangs above the map. Erica Gonzales, Harper's BAZAAR, 15 Apr. 2019 One is an astrolabe, an instrument used to measure the position of stars. Kamasi Washington, WSJ, 8 Jan. 2019 Without magnetic compasses or tools like astrolabes, the Vikings likely relied on primitive solar compasses to navigate, which uses the position of the sun to determine north. Jason Daley, Smithsonian, 9 Apr. 2018 By aligning an astrolabe perpendicular to the horizon, ancient astronomers could calculate measurements like time and position. David Mearns, National Geographic, 24 Oct. 2017

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'astrolabe.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

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First Known Use of astrolabe

14th century, in the meaning defined above

History and Etymology for astrolabe

Middle English, from Anglo-French & Medieval Latin; Anglo-French astrelabe, from Medieval Latin astrolabium, from Late Greek astrolabion, from Greek astrolabos, from astr- + lambanein to take — more at latch

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The first known use of astrolabe was in the 14th century

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Cite this Entry

“Astrolabe.” Dictionary, Merriam-Webster, Accessed 6 Dec. 2021.

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